code: def testDescending(self):
      self.assertEqual(
          DerivativeSFX()(list(numpy.linspace(1.0, 0.0, 100))),
          (0.0, 1.0),
      )
  
file_path: essentia/test/src/unittests/sfx/test_derivativesfx.py
imports: from essentia_test import *
  import numpy
label_desc: Use image node_id 5 for calling the TestDerivativeSfx obj's underlying member method code with example usage: obj.testDescending() without return types